Having a hard time figuring the easiest way to calculate this.

4 people buying party supplies and food separately on their own credit cards. They want to divide everything evenly and "square up" via Venmo.

Person 1 spent $550
Person 2 spent $80
Person 3 spent $120
Person 4 spent $150

What's the easiest way to calculate this so there aren't a bunch of redundant Venmo transactions? Who pays who what amount?

(The numbers above aren't set in stone and might change IRL)

550 + 80 + 120 + 150 = 900 / 4 = 225 per person

Person 1 pays (225 - what person X pays) to Person X

edit...

wait : fail lmao

person 2,3,4 pay the difference of what they paid and 225 to person 1

225 each, person 1 should be only receiving payments, persons 2, 3 and 4 should be sending payments to person 1:
person 2 sends person 1 $145,
person 3 sends person 1 $105,
person 4 sends person 1 $75,

Thanks. Gonna rep all responses. Appreciate the help.

This is what I was thinking but wanted to make sure I was looking at it right.

Try using an app called splitwise. Each person inputs how much they paid and whether it is to be split evenly or not. Makes group outings and trips super easy as it tells you how much you owe/are owed and takes you right to venmo with the amnt owed

Thanks for the app suggestion.

I ended up usinghttps://billzer.comwhich I think is accurate

Problem as stated in OP is trivially solved, but the generalization is more interesting (OP said the numbers are subject to change).

With 4 people, you are basically going to have a situation where 3 payments are made, or the payment data is symmetric and the problem collapses into 2 payments. An example of this is if the original payments were

Person 1: $100
Person 2: $200
Person 3: $300
Person 4: $400

Mean is $250 and person 1 owes $150, person 2 owes $50, person 3 needs to gain $50, and person 4 needs to gain $150. This is a collapsed scenario in which only 2 payments are required: person 2 gives person 3 $50, and person 1 gives person 4 $150. That's a coincidence..it will usually require 3 payments.

With any number of people, say N people, the bill can be settled by at most N-1 Venmo transactions. Instead of doing it SipNPiz's way, which is fine, consider doing the OP problem as follows:The above is a procedure that will work to make the bill even foranynumber of people and their payments, it can always be done in N-1 transactions.

But there can always be collapses....so if OP is really looking to minimize, he'd have to see for any given data set if there are any collapses. It turns out this is an NP-Hard problem and here are all the gory combinatorics details:

https://math.stackexchange.com/quest...-among-friends

Hnggg. Strong username to post. This is why I misc. Will rep off recharge

LOL @ sending any parents to anyone without itemized receipts. If those aren't being provided, OP say you spent 350,000.


Cheers

I'm on spread with numberguy, but I'll do my best to get back to this thread soon to rep for that epic post above.

Thanks again to everyone.